Compared with their sisters who have not given birth, women who have given birth vaginally do not appear to have an increased risk of urinary incontinence, according to a report in the medical journal Obstetrics and Gynecology. Rather, family factors seem to play an important role in determining risk.

Previous reports looking at the association between vaginal birth and incontinence have been plagued by various study design issues, such as the use of unvalidated self-report surveys, not making a distinction between the various types of urinary incontinence, and not considering the condition’s severity.

To further investigate, Dr. Gunhilde M. Buchsbaum, from the University of Rochester Medical Center in New York, and colleagues used a comprehensive questionnaire to assess pelvic floor disorders in 143 pairs of postmenopausal sisters that included one who had given birth and one who had not. Evaluation of urinary incontinence and genital prolapse was conducted in 101 of the pairs.

The pelvic floor is a network of muscles, ligaments and tissues that support the uterus, bladder and rectum. Symptoms of genital prolapse are characterized by the feeling that the pelvic organs are bulging into the vagina or the feeling of increased pressure in the pelvic area.

The rate of urinary incontinence among the women with children was 50 percent, not a statistically significant difference from the 48-percent rate seen among the women who had not given birth, the authors report. The type of incontinence and disease severity also did not differ significantly between the groups.

However, the same urinary status seen in one sister was often present in the other, suggesting that there is an underlying family disposition toward urinary incontinence.

“A genetic predisposition for urinary incontinence needs to be explored further because finding a genetic link to this condition would have great implications for the direction of basic research, treatment approaches, risk management, and potential prophylactic interventions,” the authors state.

SOURCE: Obstetrics and Gynecology, December 2005.